Organic electroluminescence (hereinafter referred to as “EL”) display devices making use of the electroluminescence of organic materials have a faster response speed when compared with liquid crystal display devices and have attracted attention as display devices having a wide viewing angle.
An organic EL display device has a configuration including, for example, thin film transistors (TFTs) provided on a substrate, such as a glass substrate, and organic EL elements provided on the substrate connected to the TFTs.
Organic EL elements are light emitting elements capable of emitting light at high luminance using low voltage direct current driving, and have a configuration in which a first electrode, an organic EL layer, and a second electrode are layered in this order.
An organic EL layer includes an organic compound layer including a light emitting layer, but the characteristics thereof degrade by reacting with minuscule amounts of water or oxygen, damaging the life of the display device. For this reason, in manufacturing an organic EL display device, the formation of a sealing member that prevents the intrusion of water into the organic EL elements is indispensable.
In the film formation of a sealing member, a chemical vapor deposition (CVD) device such as a plasma CVD device can be used.
In a CVD device, a film-forming gas is introduced into a chamber that has been evacuated to vacuum, a plasma is generated between an upper electrode and a lower electrode disposed in the chamber to decompose and react film-forming gas. Through this, a film that comprises reaction products is formed as a sealing film that covers the organic EL elements on a substrate disposed on the lower electrode.
The sealing film is pattern formed in any shape by using a film-forming mask (hereinafter referred to simply as “mask”) for each organic EL display device such that the connection terminals between the organic EL display device and the outside and the like are not covered.